Between January 1989 and August 1990 a new technique for percutaneous renal biopsy was evaluated in all patients undergoing native kidney biopsy in our hospital. The method combines the use of an automated biopsy device, disposable biopsy needles, and a needle guide attached to an ultrasound probe. This allows real-time ultrasound scanning throughout the procedure. All biopsies were performed by trainee nephrologists. The success of the technique was evaluated by analysis of histopathological data, and the complications of the procedure from case-notes and nursing records. During the study 192 biopsies were attempted, of which 188 (97.8%) were successful. For each biopsy a mean of 2.8 needle passes were required and 75% of these obtained cores of tissue. An average of 25 glomeruli (range 1-90) were seen per biopsy. Although microscopic haematuria was almost invariable, there were no episodes of frank haematuria and no blood transfusion or surgical intervention was required. The new method is simple, providing accurate localisation of the kidney coupled with direct visualisation of the biopsy, and results in a very high success rate. Intrarenal needle dwell time is kept to a minimum and there were only minor complications. This technique deserves more widespread use.